Dental casting device



May 10, 1927.

J. C. SHOTTON DENTAL CASTING DEVICE Filed Jan. 'r, 1923,`

Q unwf/ 1 J. C. Shel/416922 aucunes* Patented May 10, 1927.

UNITED STATES' JOI-IN C. lS-IOIYLON, OF LAKEWOOD, OHIO. n

DENTAL CASTING DEVICE.

Application filed January 27, 1923. Serial No. 815,297.

The present invention relates to a dental casting device, and has forits object to provide a device of this Character which embodies novelfeatures of construction whereby the castings which are used in thepractice of dentistry can be made with greater ease and certainty thanhas heretofore been possible.

Dental castings are'usually made of some metal suchas gold, and it isnecessary to use some means `for forcing the molten gold to flow throughthe sprue opening and enter the cavity of the mold. This can beaccomplished .by the .use of centrifugal force or by the useV of.airpressure or airsuction, the air pressure being applied to the top ofthe mold to force the molten metal into the same, while the air suctionis .applied in a reverse manner `to draw the molten metal into the mold.A n

The centrifugal process is difficult to follow when the mold is manuallyswung around in a sling device, and the 'centrifugal casting machineswhich have been devised are all costly andcomplicated. I ani also awarethat devices have been invented for using air pressure to force or drawthe molten metal into the mold, although these devices have beencomplicated and the air pressure has not been under the proper control.of the operator. K f

The object of the present invention has been to provide a dental castingdevice which is comparatively .simple and inexpensive in itsconstruction, which can be easily manipulated, which is under theperfect control of the operator at all times, and which enables acasting to be readily made, either by applying air pressure to the topof thek mold or by producing a partial vacuum at the botwtom of themold. Y

For illustrative purposes I have disclosed one particular embodiment ofthe invention in detail, although it will be understood that manymodifications and changes 'can be made in the details of constructionwithout departing from the spirit of Ithe invention, and I do not wishto be Vunderstood as restricting myselfto the particular form of theinven. tion which is shownby :the/drawings.

For a full understanding of the invention reference is to be had to :thefollowing description and accompanying drawings, in which- Figure lisaside elevation of av dental casting device which is constructed inacythe cup member.

Figure 2 is a top plan view of the base of the dental casting device,showing the conical shaping element at one end thereof and the sprueformer at the other end thereof.

Figure 3 is a transverse .sectional View through the device, showing themanner of using the device when it is utilized to pro-v -vide a partialvacuum under the inold'to/ draw the` molten metal into the cavityof themold by suction.

Figure 4 is a detail view ofthe forked arm which is applied to one sideof thebase and utilized for supporting the air cup in an invertedposit-ion when the device is used in the manner shown by Figure 3.

Corresponding and like parts are referred to in the followingdescription andindicated '80 on all of the views of the drawings by likereference characters.

Y Referring to the drawings which illustrate one ofy many possibleembodiments of the, invention, the numeral 1 designates a base S5 memberwhich has an elongated formationl and is preferably hollow, so as toreduce the l weight of the base member 'and save metal. The ends ofthebase member are shown as Y provided with perforated ears 2 which c0n-5G stitute means for securing the base to atable or other suitablesupport by the .use of fastening members. One end of the base is provided with a substantially conical shaping member 3 having a short lstemlgprojecting 95 from the apex thereof. The oppositeend of the base isprovided with a sprue former 5 which is substantially conical in shape.The sprue former is removable so that different forms and shapes ofsprue formers can` he 10U substituted as lmay be desired. The base ofthe sprue former is formed with a positioningpin 6 which is removablyreceived within 'a corresponding opening formed in the topV of the base.The apex of Jthe sprue former is formed as usual with a recess T toreceive the pin 8 upon whichl the wax pattern or matrix lSlis supported.y Y

In preparing the mold a wax impressionk or pattern 'of the cavitv inthe-tooth is made 110 in the well known manner. This wax pattern 9- issupported upon the end of a pin llt 8, and the tree end of the pin ieinserted in the recess ot the sprne `torn'ier og as indicated by dottedlinee at the right hand end oit .Figure l. il. ring; il) oit' theconventional form is next placed upon the eprue toriner` said ringsurrounding the wax pattern 9 and having; the lower edges ther-eert in aclose engagement with the top el: the :spree former. The lnold ie non*filled with a enit able investment7 and alter the investment hashardened the niold le subjected to a at lieient aniount et heat tocompletely remove or burn out the wait, no that with the pin la* removedthe mold ie ready 'tor the casting; operation. The general rnethod otforming.; the mold ie `well known to the dental prole sion and no claimto nm'rlty in baeed thereon The eprue torinc fi learee the Inold with adepree'eion o in the lop thereot, the bane olf the depreeeion behnr` inconnnunication with the elnall piteeatre t" which waa Iornied by the pinS and which lcade` downwardly to the cavity Sl which wie: tornicd by thewax pattern t) and which has the exact :drape ol the wax pattern. lnYlorniine a canti g a quantity ot molten `fold or other nie@ .ll

nlnet be placed in the depreei-:ion and forced to llow tlnonggh thepaenapge S into the eavity QI. .lhil ninet. et tourne` be done quicklybefore the molten nirtal ha` an op poi-trinity to cool and harden` andit nnnzt aleo he accomplished without the nee o l any enceseive orviolent torce, snob as would tend to rupture or break the n'iatcrial olthe mold. lfn tact, one oi the objections; to Sonie ot the previouslforlns el devices n'hieh have been utilized 't'or forcing; the nioltenmetal into the cavity han been that they reduire the une ot aconeiderable ainonnt ot torce which it ie dillicnlt to apply in euch ainan- .ner as to avoid breaking: or injuring' the mold.

:In carrying ont the present invention air pressure is utilized forl'orcingr the molten .metal l1 to lion' ilownwardly through theliniesage 8 and enter the cavity 9u. The numeral l2 deeienaten a flaredcup nieniber which is provided with a linine lil ol" sonic Suitableplaetic material, which ist adapted to engage either the upper or loweredcje et the rintl l() :ind proride an air tight joint. therewith. Theouter eden ot the air cup 1:2 may he extended inwardly, as iinlicated ati241, in order to a holdingl the plaetio lining' 'i3 in place. t handlelei projects troni the back ot the air enp and 'formed with a paeeagrelo which extend4 entirely through the handle :troni end to end thercot1and eonnnnnicateev with the air cup. The niiddle portion ot the bundlelornrcd `with an annular enlargement or rib lll which may be metal intacilitating,r the obtaining' et a tirni grip theretui` and the end otthe handle remote from the air cup :termed with a seat lll l'orengagement with a rubber bnlb 17` the flange 17 at the coupling end otthe bulb being; fitted upon a nipple lll. lily suitably nianipnlating.;1this bnlb 17 it can be caused to act in the manner of an air pun'lp7either to compren or attenuate the air in the air cup.

"When it ie deaired lo force the molten nletal into the inold by theaction ot conin d air at the lop et the inetd, the ring in L placed uponthe niiddle portion ot the bane l und the air cup lil pressed lirznlydown on the upper edile ole the ring, as; in dii-ated by l'nll linen onltigrlue l. rlhe upper oder, ol' the rino1 it) if; thinl partially en1-bedded in thev plaetie lining lil ot the air cupT with the ronult that aperfectly air tightl joint in obtained between the cup and the ring. lheuiiddle portion ot the bane niemhcr l in provided with a aerien ot tranYernely etteinling channels or depreseions if.) which are `lor thepurpose ol providing` a rcadv oleane ol escape lor air which may he.

Forced through the inrcnliucut ol the mold, it being;v underetood thatthe usual torni ol. investment `which ie employed by dentists ispei-rione to air. The niolten `gold ll havingI been lrumfionely placedin the depression 5, a squeezing or compression ot the bulb 17 will nowcompress the air within the halb and air cup eo that the mollen froidwill be l'orced by thi` air pleasure into the cavity ot the nrold. 'lhiscan be done very quick ly so that there will be no danger olf thenoolten Lgold cooling` and hardening before it can be 'forced into thecavity, and there is no violent or excessive pressure such as niitehttend to rnptnre the material oi the nrold. tCare nlnet be taken, olfcourse, not to releane the bulb li while the air cup is still inengagienient with the ringl and before the grold hae had an opportunityto harden, as other rise the return ot the rubber bulb to its` originalposition would tend to attenuate the air Within the bulb und air enp andperhaps draw the reid u p ont ol.i the inold cavity. Either the bulb i7nlnet be held in a conipreeeed condition until a'tter the gold hashardened, or the air cup must be dsengaged lroni the ring;- betere thebulb is released.

ln order to Smooth the surface ot the plastic lining` 13 and spread itnnil'orinly over the interior ol the air cnp l). the cup may be appliedto the shaping' nieinber 3, as indicated by dotted lines on Figure l.The stein l ol the shaping member then entere the lower end ot thepaeeage 15 ot the handle so that the plastic material is preventedl'roin entering the said paeeage. lllhile in this position the air cupcan be rotated npon the shaping` nieinber l and pressed trinly downvardthereon. Thin will `reeult in distrilmting the plastic n1a terialnnilorinly over the interior of the air cup and leaving the same with asmooth surface so that it willeectively engage the edge Yoi. a ring ltoform an air tight con nection therewith. Any suitable' form of plasticlining may be used, although I have found that satisfactory vresults areobtained where a mixture of uller7s earth and glycerine are used. Theuse ,of glycerine enables a plastic material to be formed which willretain its plastic condition 'for a long period ot' time.

Under some conditions 'it may be found preferable to produce a partialvacuum under the mold and thereby Lutilize atmose pheric pressure forforcing the molten metal into the mold cavity. Nhen this is' desired theair cup l2 may be supported inan inverted position by means ofV abracket 2O projecting from one side of the base member 1, as'indicatedby-Figure 3. The bracket is formed with a plug 21 which can be removablyscrewed into an opening 22 in the base member. The outer end of thebracket is forked and adapted to engage an annular groove or seat 23formed at the back of the` cup member. Suitable means such as a. strap24 is provided for holding the bulb 17 partially compressed. One end ofthe strap 24 is shown as connected to a ring 25 which is fitted upon thebracket 20, while the other end of the strap is provided with a secondring 26 which detachably engages a linger 27 at the outer end of thebracket. The plastic lining 13 is caused to engage the lower edge of thering of the mold, as indicated by Figure '3, and the molten gold ormetal 11 is th-en placed in the depression 58L of the mold, whereuponthe ring 26 is disengaged `from the finger 27. The elasticity of therubber bulb l7lthen causes it to tend to return to its normal position,with the result that the air withinthe bulb and air cup isattenuated.The partial vacuum which is thus produced E under the mold tends to drawair through the pervious investment material, with the result that theoutside atmospheric vpressure acts upon the molten gold to force it intothe mold cavity. This is accomplished easily and quickly without anyviolent effort, and there is nothing` ywhich could rupture or break thematerial ot' the mold. After the molten metal has hardened theinvestment material is, ot course, broken and the casting obtained.

The provision of some means suchas the plastic lining 13 of the aircupto obtain an air tight connection with the ring member of the mold isimportantwhere air pressure is utilized to-force the molten metal intothe mold cavity, and it is also important that the air pressure shall beunder the complete control of the operator, since it is necessary towork quicklyand get the molten gold into the mold cavity before it hastime to harden. The rubber bulb 17 `provides in effect an air pump whichcan be utilized either for compressing or attenuating the air, accordingto whether it isY desired to torce the gold into the mold cavity by airpressure applied from the top, or draw the molten gold into the moldcavity by suction applied to the bottom. lt will be obvious that variousforms of such pump devices for controlling the air pressure may be usedwith substantially the same results and are within the scope of thisinvention.

yHaving thus. described my invention what I claim as new and desire tosecure by Letters Patent is, Y

1. A dental casting device including a ring, a mold formed within thering of material whichis pervious to air, a removable cup adapted toengage the edges of the ring, a resilient bulb connected tothe interioroi l the cup for varying the air pressure therein,

tight connection between the ring and the cup with only a lightpressure.

2. In a casting device of the character described, the combination witha mold hav ing a body portion formed of material pervious to air, an aircup adapted to fit the mold, means for supporting the air cup, aresilient bulb applied to the cup for varying the air pressure in thesame to force molten metal into the mold cavity, and re! leasable meansfor holding the bulb par tially compressed.

3. A casting device of the character described, comprising an air cupadaptedr to tit over the ring of a dental mold, a plastic lining for thecup, and a shaping member corresponding in configuration to the size of'the ring and the interior of the cup and vinsertable therein to shapeand smooth the vplastic material.

4. A casting device of the character described, comprising an air cupadapted to it over the ring of a dental mold, a tubular handle for thecup, means communicating with ythe cup through the tubular handle Jforvarying the air pressure therein when it is applied to a dental mold, aplastic lining for the cup, and a shaping member corresponding inconfiguration to the size ot the ring and the interior oi the cup andinsertable therein for shaping and smoothing the plastic material, saidlshaping member being formed with a stem which enters the passa-ge ofthe tubular handle to exclude the plastic material romthe said passage.

5. A casting device of the character described, including a base havingaportion of the surface thereof formed with depressions adapted to serveas air outlets at the base of a'dental mold placed thereon, an air cupadapted to be applied to the top of the ,gz o 1,6%,437

dental mold, plastic material within the oir cup for producing on oirtight eonneel'ion with the, denial mold, ineens 'for producing :111 nii'pressure within the nii' enp lo :lfoi'ee :1,11* downwardly tln'ongliille pervions body portion olP l'he niolil :inil ezinse molten niezil toenter the, niolil eovily, :unl :i ,ellzilviing ele- Jneni` pi'ojeelingfrom lie liaise, :ind :nlnplxeil to ieeeive ille :iiil enp for:inioelliing unil ilirilriliniing [lie pliinie linini;v Vwiiliin illemine.

l. A (lontani casting (leviee l'oi' iienlnl molds eoniprieinpl :1, enpineinliei', :i lining for szliil eilp member composer! oi plansiieinullei'iiil in whieli lille mo|llin|l nienibeif ir; receivable lopi'oviile, i:` lezili-pioolf eonnee- Lion, anni un :iiieonneetioneonnnnnieniing with the enp il'ol varying ille oir pressure within midcup.

7. A Llenl'ul meting device, for dental inolds Comprising :i conical cupmember, :L liningd conforming to the Shape oli2 the Walls of the enp andcomposed of plastic material in wliiell 'he molding member is reeeivnble llo provide a lealeproof joint, and

:in alii' bulli eoninnniicating with the enp 'for pioilnein}r pressureoi' suction williin the eop.

es. Dental vueling :Lppzn'nins ol'v (lie einen (!e ei'il ed comprising:i enppoi'l, u lmzning member removably mounted thereon, u enp member:nlnpieil to eoaleli willi sziicl l'in'ining;` nieinbel' und lizeving :iplusiie lininguilnplieil lo eoni'orni lo ille rslmpe ol lille formingInienibei' when the leiter ie anfranlgeil in eonlizufi'ing i'elzilionilieielo, und :in nii' bull) oonnnnni@ culling with ille nieiioi ol,sani enp.

vln lentiniony .vliereol iY nliix my s1gi1ut-n1'e.

